Class blog for sharing and commenting on current events in biology.

Thursday, January 16, 2014

The Fish That Could Have Lived in Two Worlds: The Tiktaalik

The Fish That Could Have Lived in Two Worlds: The Tiktaalik

Amos, Jonathan. "Tiktaalik: Iconic Fossil's Rear Parts Described." BBC News. BBC, 14 Jan. 2014. Web. 16 Jan. 2014. <>.

A Summary:
In this endearing article, a key fossil find in last 10 years finally opens its doors to scientists, who are absolutely intrigued by the finding. A creature that is 375 million years old is now named the Tiktaalik (teek-TAL-lik). This newfound fossil is considered essential for its appearance of looking halfway between a fish and a land animal. This helps provide more knowledge on how evolution went from a life in water to a more earthly environment. Early specimens only contained the front most part of the fossil, yet with the new specimens scientists have been able to study the rear parts of the creature, which seem to be vital for research. The PNAS or the Proceedings of the National Academy of Sciences, has reported an important pelvic bone and tail fin.
This elaborates on how the Tiktaalik moved through water during the Devonian Period of Earth. The creature is known as a tetrapodomorph, a kind of mobile vertebrate. The Tiktaalik was about 2.5 meters, which is about 8.2 feet long. It bares resemblance to a fish, as it has scales and fins with webbing. The Tiktaalik however, also had a flat head, shoulders, forearms, and wrist bones that repeated themselves later.  It was said to be fully-land living, a four-limbed animal.       
The early analysis of the creature was based on fossils in the Canada’s High Arctic on Ellesmere Island in 2004. This research only concentrated on the front most part of the creature. After cleaning and preparing other specimens, that were gathered at the same time as the original specimens, scientists have been able to same something certain about the Tiktaalik’s back region.
They have a thick powerful rear fin with a surprising pelvic “belt” that would have been able to support its rear fins. Although the impressions of these features are limited in the fossil rock, it has been made clear by the size of its pelvis that the creature’s hind fins were large. "The pelvis is as large as the shoulder girdle, and that's not what we would have expected in this finned stage in the fin-to-limb transition. We would have expected the pelvic fins to be smaller," stated Doctor Ted Daeschler, of the Academy of Natural Sciences of Drexel University in Philadelphia. A team from the PNAS said that the pelvis being larger means that the Tiktaalik’s locomotion depended on a quartet of strong limbs. This feature in the creature was already being emphasized in fish fins long before land animals had “four wheel drive”.
The latest research done, also allows scientists to make a new simulation of how the rare Tiktaalik looked like and moved like in its environment. Its fins were there to be used as paddles to swim, but also could have been used in a leg-like manner in certain occasions. Dr. Daeschler said, "Tiktaalik probably had the ability to use those fins as props to move along, using them to push along the shallow bottom, to work its way through plants; and, who knows, maybe it got out of the water briefly if it needed to move over to another watercourse.” It was not meant to be specialized on land in any way, though. Although the creature has been discovered to have major indicators of being both a land and water animal, the Tiktaalik’s reproduction, its physical senses, its hunting, and its breathing all related back to the water.   

            Although knowing that scientists are making new discoveries about a type of dinosaur creature may seem very cliché in why it’s worth it, I thought there was a huge impact on society on what has been going on here. It’s important to start off with the fact that the discovery alone is already affecting society on how advanced we have gotten. To think that a little while ago, scientists did not know as much about this odd creature and now it has become a revelation for it’s ability to be on land and water. Things we wouldn’t have been able to know without know that it has a large pelvis, giving it speed in swimming and the leg-like fins giving it an ability to walk! Another reason why this is impacting society is that it could lead to more discoveries and theories of evolution. It may not be the most revolutionary discovery, but it is most definitely a start to new ideas on how and why we got where we are today. Whether you are a science fan or not knowing about evolution is something that we all have interest in. We’re all leaning on Darwin’s theory of evolution, which is very airtight, but what if there is more elaboration to his theory? What if there is a missing puzzle piece in all of it? Our knowledge of marine wildlife could advance a lot in terms of their anatomy and maybe ways of their nature. This is a compelling opportunity to start new research on how to help animals in the water is they’re ever in any endangering position in the near future.

            This article from BBC News is almost perfect for me, considering I love their writing style, and they always seem to tackle topics that are very intriguing for me. This was not meaty, yet it contained all the information I could have asked for from the Tiktaalik. It’s vocabulary was not too advanced but also not to past my level of reading. I was extremely impressed that the article didn’t need to use as much quotes as a lot of articles use. It seems that most articles depend a lot on quotes to make it seem real and authentic but what journalists don’t realize is that they need to write an article that the public can enjoy reading.
 I could have chosen a fairly good article from the New York Times that was written with a dull and complicated vocabulary, and had a base built on with quotes from scientists and researchers. But when I started reading this article, the writing of the author instantly hooked me. Even if the topic wasn’t as interesting as it was, I think I still would have enjoyed reading it because of the fluidness that the journalist had to his writing. It wasn’t blocky and very tight with facts and quotes. The article itself ha d a personality of its own that gave me a very strong liking to it.
There are very few ways in which I could put that I didn’t like this article, but I do wish they would have elaborated a little more on the Tiktaalik itself. Although they did have a section to the article describing the creature, I felt it was slightly vague. Other than that, this article was truly enjoyable to read an I strongly recommend you all take a few minutes to at least read the beginning. 


  1. I thought your summary was really good, you gave a detailed explanation and talked about the important facts from the article. I liked how you didn’t go overboard with information and used words and terms that were easy to understand. Over all your summary was simple, but was able to cover the key ideas from the article you chose. I have never heard of an animal like the Tiktaalik, and thought the topic you chose was very interesting and important in scientific research. The idea that there was an animal “that could have lived in two worlds” is really significant when it comes to evolution and how different species developed. It’s kind of crazy how scientists were able to find and examine a fossil from a fish that lived 375 million years old. You did a good job explaining what the Tiktaalik looked like, and I got a better understanding of what exactly it is. From the way you described it, the Tiktaalik seems to be odd looking creature that is powerful and compatible in both water an land. You also explained what a tetrapodomorph was, which, once again, I have never heard of, so it was nice to learn something new. It would have been interesting to know what exactly its lifestyle was like and how it lived, but I don’t think that was in the article. Going back to the relevancy and significance of this article, I thought you did a nice job explaining why this is so important to science. I liked how you said that this discovery may lead to additions to the theories and beliefs of evolution, and how you pointed out that just discovering and analyzing this fossil is a big deal. Over all, you chose an interesting article and your summary was really good.

  2. I agree with Yosman in that your summary was very strong.

    There are many reasons why this particular fossil fascinates scientists. It is partly because it is what we call a "transitional fossil" meaning that it links between two distinct life forms; in this case fish and amphibians. Transitional fossils are key in understanding how evolution could spawn such diversity of life from a common ancestor.

    Here is a neat link if you want to learn more about Tiktaalik:


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